The present invention relates to buckets of the type which are used in earth-moving machines such as excavators, although such buckets also are used in all types of heavy machinery designed to move loose material, even for loading purposes.
Thus, buckets of the type to which the present invention relates are capable of being used on excavators, on front loaders, and in general on earth moving machines which are designed to handle loose material.
The invention relates in particular to the cutting edge region of such a bucket where it is provided with teeth.
At the present time, in order to accommodate such teeth, receptacles therefor are constructed of a pair of half-shells which may be welded together, with the cutting edge of the bucket being shaped suitable so as to support such shells which in turn carry the teeth. These shells are generally made of a hardened and tempered steel of approximately 90 kg/mm.sup.2, while the cutting edge of the bucket wall is made of a relatively soft steel.
Conventional structures of the above type have certain disadvantages and inconveniences in that the cutting edge which is made of soft steel is exposed to extremely severe wear. At one time it had been attempted to provide such cutting edge regions of the buckets with a hardened and tempered steel, but even then the bucket wall was not sufficiently resistant to wear and at the same time the construction of such buckets was extremely expensive and they were difficult to purchase on the market in the required dimensions.
As a result this latter type of construction was abandoned and instead a construction was provided according to which angled members of hardened and tempered steel having a relatively great resistance to wear were welded to the cutting edge region of soft steel of the bucket wall itself. Thus, the intention was to protect the cutting edge region of the bucket wall in the space between the teeth with a construction of this type. However, satisfactory results were not achieved because of the small mechanical strength at the coupling between the reinforcing elements and the cutting edge region of the bucket wall. In addition, unsatisfactory results were obtained because the shells which were hardened and tempered for only 90 kg/mm.sup.2.
Thus, up to the present time there has been no satisfactory solution to the problem of providing the front cutting edge region of a bucket of the above type with the properties required to resist wear while at the same time being capable of being economically constructed in a material such as soft steel which can be readily found on the market in the required dimensions. In other words, up to the present time it has not been possible to strengthen the soft steel of the cutting edge region of a bucket in an adequate manner which will provide for the bucket a long operating lift while at the same time providing constructions which can readily be used for buckets of all dimensions.